/*******************************************************************************
 * Copyright (c) 2007 University of Oslo.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     University of Oslo - initial API and implementation
 *******************************************************************************/

package com.cea.papyrus.diagram.sequence.sedi.figures;

import static com.cea.papyrus.diagram.sequence.sedi.model.util.ModelUtil.neIsInstance;

import org.eclipse.draw2d.ConnectionAnchor;
import org.eclipse.gef.requests.CreateConnectionRequest;
import org.eclipse.gef.requests.ReconnectRequest;
import org.eclipse.uml2.uml.Message;

import com.cea.papyrus.diagram.sequence.sedi.editor.MessageSpecification;

/**
 * TODO Document
 * 
 * TODO There is a good amount of common code shared between the
 *      different anchor policies. Is it possible to share it formally as well?
 *  
 * @author frankd@ifi.uio.no
 */
public class InteractionUseAnchorPolicy implements AnchorPolicy {
	public boolean acceptConnectionCreate(ConnectionAnchor anchor, CreateConnectionRequest request) {
		return (request.getNewObject() instanceof MessageSpecification);
	}

	public boolean acceptConnectionComplete(ConnectionAnchor anchor, CreateConnectionRequest request) {
		return check(request.getNewObject(),
					 request.getSourceEditPart(), 
					 request.getTargetEditPart());
	}
	
	public boolean acceptReconnectSource(ConnectionAnchor anchor, ReconnectRequest request) {
		return check(
				request.getConnectionEditPart().getModel(),
				request.getTarget(), // actually gives the new source
				request.getConnectionEditPart().getTarget()); 
	}

	public boolean acceptReconnectTarget(ConnectionAnchor anchor, ReconnectRequest request) {
		return check(
				request.getConnectionEditPart().getModel(),
				request.getConnectionEditPart().getSource(),
				request.getTarget());
	}

	private boolean check(Object connection, Object source, Object target) {
		// Don't allow messages to self
		// Also only allow real messages
		return (source != target
				&& (neIsInstance(connection, Message.class)
					|| connection instanceof MessageSpecification));
				    //|| connection == UMLFactory.eINSTANCE.getMessage()));
	}
}

